| 9 | ÷ | 4 | − | ( | 7 10 | − | a | ) | × | 5 | ÷ | 7 | = | 15 | ÷ | 7 |
| Left side of the equation = | 9 4 | − | ( | 7 10 | − | a | ) | × | 5 7 |
9 4 | − | ( | 7 10 | − | a | ) | × | 5 7 | = | 15 | ÷ | 7 |
| Left side of the equation = | 9 4 | − | 7 10 | × | 5 7 | + | a | × | 5 7 |
| = | 9 4 | − | 1 2 | + | a | × | 5 7 |
| = | 7 4 | + | 5 7 | a |
7 4 | + | 5 7 | a | = | 15 | ÷ | 7 |
| Right side of the equation = | 15 7 |
7 4 | + | 5 7 | a | = | 15 7 |
5 7 | a | = | 15 7 | − | 7 4 |
5 7 | a | = | 11 28 |
| a | = | 11 28 | ÷ | 5 7 |
| = | 11 28 | × | 7 5 |
| = | 11 4 | × | 1 5 |
| a | = | 11 20 |
| a | = | 0.55 |